# US 12,181,702 B2 · Distributed light projection device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,702 B2 - Document ID: US12181702B2 - Status: Granted - Kind: B2 - Application number: 17/153,596 - Filed: 2021-01-20 - Published: 2021-07-29 - Granted: 2024-12-31 - Earliest claimed: 2020-01-24 - Assignees: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Applicants: Commissariat à l'Énergie Atomique et aux Énergies Alternatives - Inventors: Christophe Martinez; Daivid Fowler; Basile Meynard - Web page: https://patentgrep.com/patent/US12181702B2 ## CPC - G02B 6/0035: {provided on the surface of the light guide or in the bulk of it} - G02B 6/0038: {Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide} - G02B 6/006: {to produce indicia, symbols, texts or the like} - G02B 6/0076: {Stacked arrangements of multiple light guides of the same or different cross-sectional area} - G02B 6/124: Geodesic lenses or integrated gratings - G02B 6/34: utilising prism or grating {(G02B6/293 takes precedence)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A Distributed light projection device, including: one or a plurality of waveguides; and above each waveguide, a plurality of extraction cells coupled to distinct portions of the guide, each extraction cell including first and second stacked diffraction gratings. ## Claims ### Claim 1 A distributed light projection device, comprising: a plurality of waveguides; and above each waveguide of the plurality of waveguides, a plurality of extraction cells coupled to distinct portions of each waveguide, each extraction cell in the plurality of extraction cells comprising stacked first and second diffraction gratings, wherein the first and second diffraction gratings within each extraction cell in the plurality of extraction cells are offset by a position offset value and different extraction cells in the plurality of extraction cells have different position offset values between the first and second diffraction gratings, whereby the different extraction cells have different extraction coefficients; wherein each waveguide of the plurality of waveguides is a monomode waveguide; wherein, in each extraction cell, the first and second diffraction gratings have a same pitch; wherein the second diffraction grating extends above at least one portion of the first diffraction grating and covers the at least one portion of the first diffraction grating; wherein the extraction coefficient comprises a percentage of guided light extracted by each extraction cell; and wherein each extraction cell is formed apart in a horizontal plane. ### Claim 2 (depends on 1) The distributed light projection device according to claim 1, wherein, for each waveguide of the plurality of waveguides, the different extraction cells coupled to the waveguide have the position offset values between the first and second diffraction gratings decreasing as a distance to an input end of the waveguide increases, such that the different extraction cells have extraction coefficients increasing as the distance to the input end of the waveguide increases. ### Claim 3 (depends on 1) The distributed light projection device according to claim 1, wherein: the first and second diffraction gratings of an extraction cell of a waveguide of the plurality of waveguides laterally extend above at least one other waveguide of the plurality of waveguides and form an extraction cell of the at least one other waveguide, and each distinct portion of the waveguide includes an area of a respective surface of each of the plurality of waveguides. ### Claim 4 (depends on 1) An image projection device, comprising the distributed light projection device according to claim 1, and, opposite each extraction cell of the distributed light projection device, a holographic element for orienting light extracted by the extraction cell. ### Claim 5 (depends on 1) An optical phase-control network comprising the distributed light projection device according to claim 1 and, upstream of the distributed light projection device, a device for modifying the phase of light injected into each waveguide of the distributed light projection device. ### Claim 6 (depends on 1) The distributed light projection device according to claim 1, wherein the first and second diffraction gratings of each extraction cell are formed of strips of material. ### Claim 7 (depends on 1) The distributed light projection device according to claim 1, further comprising a layer separating the first and second diffraction gratings of each extraction cell. ### Claim 8 (depends on 1) The distributed light projection device according to claim 1, further comprising at least one laser source having a controllable intensity configured to inject a light beam into each waveguide. ### Claim 9 (depends on 3) The distributed light projection device according to claim 3, wherein the plurality of waveguides are located in a same plane parallel to a surface of a substrate comprising the horizontal plane, and wherein the plurality of waveguides extend over at least a portion of the substrate. ### Claim 10 (depends on 3) The distributed light projection device according to claim 3, wherein the respective surface of each of the plurality of waveguides is arranged spaced apart in the horizontal plane in a first direction. ### Claim 11 (depends on 4) The image projection device according to claim 4, further comprising, opposite each extraction cell, a controllable element for activating or deactivating the extraction cell. ### Claim 12 (depends on 4) The image projection device according to claim 4, comprising no controllable elements for activating or deactivating the extraction cells. ### Claim 13 (depends on 6) The distributed light projection device according to claim 6, wherein each position offset value comprises a distance between a first edge of a first strip and a second edge of a second strip of the strips of material. ### Claim 14 (depends on 6) The distributed light projection device according to claim 6, wherein the strips of material have a same width. ### Claim 15 (depends on 10) The distributed light projection device according to claim 10, wherein each area is spaced apart in the horizontal plane in a second direction. ### Claim 16 (depends on 15) The distributed light projection device according to claim 15, wherein the stacked first and second diffraction gratings are stacked in a vertical plane perpendicular to the horizontal plane. ### Claim 17 A distributed light projection device, comprising: one waveguide; and above the waveguide, a plurality of extraction cells coupled to distinct portions of the waveguide, each extraction cell in the plurality of extraction cells comprising stacked first and second diffraction gratings, wherein the first and second diffraction gratings within each extraction cell in the plurality of extraction cells are offset by a position offset value and different extraction cells in the plurality of extraction cells have different position offset values between the first and second diffraction gratings, whereby the different extraction cells have different extraction coefficients; wherein the waveguide is a monomode waveguide; wherein, in each extraction cell, the first and second diffraction gratings have a same pitch; wherein the second diffraction grating extends above at least one portion of the first diffraction grating and covers the at least one portion of the first diffraction grating; wherein the extraction coefficient comprises a percentage of guided light extracted by each extraction cell; and wherein each extraction cell is formed apart in a horizontal plane.